Shutter Island, an isolated landmass that houses the Ashecliffe Hospital for the Criminally Insane, contains far more than just a group of unstable criminals. But the secrets about this remote place are more guarded than the patients held prisoner on the island.

“Shutter Island” is a masterpiece packed with thrills and shock. The story takes so many twists and turns that the end is still unpredictable, despite ample foreshadowing.

Set in 1954, the film begins with U.S. Marshals Teddy Daniels (Leonardo DiCaprio) and Chuck Aule (Mark Ruffalo) going to Shutter Island to investigate a missing patient. The case gets more intricate as the two uncover secrets about the prison. The marshals are soon entangled in a vast conspiracy involving unethical doctors and mysterious disappearances.

“Shutter Island” is a departure from director Martin Scorsese’s usual mob movies and historic-themed films, more closely resembling “Cape Fear” than “Taxi Driver” or “Gangs of New York.” He takes elements of his past work, combining corrupt organizations with past eras to create a disquieting but realistic world. The audience, like the characters, is constantly forced to reevaluate what is true and what is imagined. Thanks to Scorsese’s direction, the film never becomes predictable or loses its mystery.

The cinematography is reminiscent of Alfred Hitchcock’s films. It powerfully contrasts panoramic scenes of the island with tight close-ups of the claustrophobic interiors and creates an atmosphere of paranoia and tension.

The film’s score consists mostly of contemporary classical pieces. With its loud crescendos and long, quiet lulls, the music seems to echo the storm that batters the island. This divide between soft music and elevated suspense in the scene adds to the unsettling mood.

The acting is the strongest asset to this character-driven drama. DiCaprio works with Scorsese for the fourth time, having previously starred in “Gangs of New York,” “The Aviator” and “The Departed.” His portrayal of Daniels is impressive, intense and sometimes heartbreaking as he alternates between mourning his long-dead wife and raging at the institution’s head psychiatrist (Ben Kingsley).

The supporting actors complement DiCaprio’s performance with strong performances of their own. Ruffalo is soft-spoken and easygoing in contrast to DiCaprio’s expressive, emotional Daniels. Ruffalo is believable and well cast in the supporting role.

Jackie Earle Haley, most famous for his role in “Watchmen,” makes a creepy cameo as a patient in the mental institution. His bruised face and raspy voice create a haunting vision that frightens audiences.

Michelle Williams is the weak link in the otherwise excellent cast. In her final scenes as Daniels’ wife, she displays real emotion, but for most of the film, her performance is flat.

“Shutter Island” could easily have become a typical genre film, relying on cackling villains and creatures leaping out of the dark to achieve cheap scares. However, Scorsese’s dramatic direction and the actors’ remarkable talents take the film beyond the typical thriller, leaving the audience excited, unsettled and never disappointed.

“Shutter Island” was written by Laeta Kalogridis and directed by Martin Scorsese.